1. Field of the Invention
The present invention relates to a rotary-type bag filling and packaging machine and more particularly to an improvement in a rotary-type bag filling and packaging machine.
2. Description of the Related Art
In a typical rotary-type bag filling and packaging machine, a plurality of pairs of grippers for clamping two side edge portions of a supplied bag and thus holding the bag in a suspended position are provided at regular intervals on a periphery of a rotary table that rotates continuously or intermittently in one direction on a horizontal plane, and these gripper pairs travel in a rotational manner in one direction by the rotary table, either continuously or intermittently, so that various packaging operations, such as opening the mouths of bags, filling the bags with the material to be packaged, and sealing the mouths of the bags, are performed in a sequential manner to the bags held by the grippers.
The above-described various packaging operations are performed by packaging apparatuses, and one type thereof is a synchronized-type packaging apparatus. This synchronized-type packaging apparatus includes a plurality of packaging members which are provided in conjunction with each one of pairs of grippers and raised and lowered at a predetermined timing while traveling in a rotational manner in synchronism with the gripper pairs.
For example, a rotary-type bag filling and packaging machine described in Japanese Patent No. 2884064 includes a synchronized-type packaging apparatus that is provided with a plurality of filling funnels as the packaging members. The filling funnels are provided in conjunction with gripper pairs and raised and lowered at a predetermined timing while traveling in a rotational manner in concert with the gripper pairs.
The synchronized-type packaging apparatus in a rotary-type bag filling and packaging machine described in Japanese Patent No. 3742042 includes a plurality of filling funnels as its packaging members, and another synchronized-type packaging apparatus in this bag filling and packaging machine includes a plurality of gas injection nozzles as its packaging members. The filling funnels are provided in conjunction with gripper pairs, and gas filling nozzles are provided in the filling funnels; and the filling funnels and the gas filling nozzles are raised and lowered at a predetermined timing while traveling in a rotational manner in concert with the gripper pairs.
The synchronized-type packaging apparatus in a rotary-type bag filling and packaging machine described in Japanese Patent Application Laid-Open (Kokai) No. 2008-308204 includes a plurality of gas injection nozzles or liquid filling nozzles as the packaging members. The nozzles are provided in conjunction with gripper pairs and are raised and lowered at a predetermined timing while traveling in a rotational manner in concert with the gripper pairs.
The synchronized-type packaging apparatus of a rotary-type bag filling and packaging machine described in Japanese Patent Application Laid-Open (Kokai) No. 2007-126208 includes a plurality of pairs of aperture guide members (also serving as gas injection nozzles) as the packaging members. The aperture guide member pairs are provided in conjunction with a pair of grippers, and they are raised and lowered, as well as opened and closed, at a predetermined timing while traveling in a rotational manner in concert with the gripper pairs.
Though Japanese Patent Application Publication (Kokoku) No. H2-27235 is not related to a rotary-type bag filling and packaging machine, it describes a container capping apparatus; and in this container capping apparatus, a plurality of plug-holding mechanisms are raised and lowered at a predetermined timing while traveling in a rotational manner in concert with container-holding mechanisms.
In the above-described rotary-type bag filling and packaging machines, there is a case that a single-type packaged product (of the same bag size, the same bag shape, and the same material to be packaged, for instance) is manufactured, and there is another case in which it is desired that they produce two or more different types of packaged products as occasions demand. In the latter case, when the packaged product to be manufactured is changed, such a situation would occur that both location of installation and raising/lowering operations of the packaging members be changed so that they match the specifications suited to the packaged product to be manufactured.
This situation will be explained below referring to the bags of FIGS. 4A and 4B (in which the packaging members of a synchronized-type packaging apparatus are liquid filling nozzles).
In FIG. 4A, the bag to be filled is an ordinary quadrangular flat bag 1 (called “ordinary flat bag” or “flat bag” hereinafter), while in FIG. 4B the bag is an irregularly shaped flat bag 2 that has a spout 2a in the top corner section (hereinafter called “irregularly shaped bag”). The bag width and the bag length (or height) of the two bags are identical. For these examples, the location of installation and the height for which liquid filling nozzles 4 are raised and lowered are assumed to meet the specifications for each bag.
For the bag shown in FIG. 4A, the location of installation of the liquid filling nozzle 4 is set to the location of the center Mc (shown by a dashed line) in the bag width direction of the mouth of the flat bag 1 that is held by a pair of grippers 3. This central location Mc of the bag mouth coincides with the location of the center Gc of the gripper pair (which is the same as the location of the center of the flat bag 1 in the bag width direction). In addition, the raising/lowering range H of the liquid filling nozzle 4 is set so that it is between the ascended upper end position Hu and the descended lower end position Hd.
For the bag shown in FIG. 4B, though the location of installation of the liquid filling nozzle 4 is set to the location of the center Mc in the bag width direction of the mouth of the irregularly shaped bag 2 held by a pair of grippers 3, this central location Mc is offset from the location of the center Gc of the gripper pair (which is the same as the location of the center of the irregularly shaped bag 2 in the bag width direction) by a distance W in the circumferential direction of the rotary table on which the grippers 3 are provided or in the width direction of the bag. In addition, in the case of the irregularly shaped bag 2 of FIG. 4B, the location where this bag is clamped by the gripper pair 3 is slightly lower than that where the flat bag 1 of FIG. 4A is clamped by the grippers, and therefore, the ascended upper end position Hu of the liquid filling nozzle 4 is set higher than the ascended upper end position Hu for the flat bag 1 and, furthermore, the descended lower end position Hd of the liquid filling nozzle 4 is set to be closer to the bottom of the irregularly shaped bag 2 in order to prevent foaming and splashing that would occur during the filling process, and thus the raising/lowering range H differs from the raising/lowering range H in the case of the flat bag 1 of FIG. 4A.
When in the above-described rotary-type bag filling and packaging machines flat bags 1 shown in FIG. 4A have been worked and filled with contents, and the bags to be processed are to be changed to irregularly shaped bags 2 shown in FIG. 4B, then it is preferable to change the location of installation and the raising/lowering range of the liquid filling nozzle 4 used as the packaging member to those illustrated in FIG. 4B.
However, since the liquid filling nozzles 4 (corresponding in number to the gripper pairs 3) are provided in a plurality of numbers in the filling and packaging machine, the operation of changing the location of the installation of all the liquid filling nozzles 4 in the circumferential direction is extremely complicated and burdensome, causing unavoidable productivity drop. This is a problem not only for the liquid filling nozzles 4 illustrated in FIGS. 4A and 4B but also for all packaging members of synchronized-type packaging apparatuses including, for example, gas injection nozzles, filling funnels, and the like.
In addition, any packaging members used in the conventional synchronized-type packaging apparatuses are constructed so that they are raised and lowered by a cam mechanism that functions as a drive source for the packaging members, and this cam mechanism is integrally incorporated in the body of the packaging machine (of the above-described four Japanese patent references). For this reason, changing the manner of the raising/lowering actions of the packaging members (which, in addition to the raising/lowering range, also includes raising/lowering timing, raising/lowering speed, raising/lowering frequency per filling, etc.) is substantially difficult. Even if the drive sources used to raise/lower the packaging members are replaced with air cylinders (as disclosed in Japanese Patent Application Publication (Kokoku) No. H2-27235), it is still quite difficult to change the raising/lowering range and raising/lowering speed.